Systems and methods for changing operation modes of the optical filter of an imaging device

ABSTRACT

A system includes a storage device storing a set of instructions and at least one processor in communication with the storage device. When executing the instructions, the at least one processor is configured to cause the system to obtain a first operation mode of the optical filter and determine a brightness value of visible light of ambient light. The at least one processor may also cause the system to obtain a brightness threshold related to the first operation mode, compare the brightness value of the visible light of the ambient light with the brightness threshold, and determine whether a switching condition is satisfied based on the comparison result. Upon the determination that the switching condition is satisfied, the at least one processor may further cause the system to switch the first operation mode of the optical filter to a second operation mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/260,332 filed on Jan. 29, 2019, which claims priority to aContinuation of International Application No. PCT/CN2017/094116 filed onJul. 24, 2017, Chinese Patent Application No. 201610613028.1 filed onJul. 29, 2016, the contents of each of which is hereby incorporated byreference to its entirety.

TECHNICAL FIELD

The present application generally relates to image acquisitiontechnology, and more particularly, to systems and methods for changingoperation modes of an optical filter of an imaging device.

BACKGROUND

An optical filter is a widely used component in an imaging device. Theoptical filter may have different operation modes that are suitable fordifferent imaging scenarios (e.g., different periods of a day ordifferent ambient light in the environment). The operation mode of theoptical filter of the imaging device may need to be adjusted accordingto a particular imaging scenario. Thus, it may be desirable to developsystems and methods that may change operation modes of the opticalfilter of the imaging device automatically and efficiently.

SUMMARY

In one aspect of the present disclosure, a system may include a storagedevice storing a set of instructions and at least one processor incommunication with the storage device. When executing the set ofinstructions, the at least one processor may be configured to cause thesystem to obtain a first operation mode of the optical filter anddetermine a brightness value of visible light of ambient light. Theambient light may include infrared light and the visible light. The atleast one processor may also be configured to cause the system to obtaina brightness threshold related to the first operation mode and comparethe brightness value of the visible light of the ambient light with thebrightness threshold. The at least one processor may further beconfigured to cause the system to determine whether a switchingcondition is satisfied based on the comparison result. In response tothe determination that the switching condition is satisfied, the atleast one processor may further be configured to cause the system toswitch the first operation mode of the optical filter to a secondoperation mode.

In some embodiments, the at least one processor may also be configuredto cause the system to obtain a first image captured by the imagingdevice with visible light, a second image captured by the imaging devicewith infrared light, and a third image captured by the imaging devicewith the ambient light. The at least one processor may further beconfigured to cause the system to determine a first difference betweenthe first image and the second image, a second difference between thesecond image and the third image, and a G value related to the thirdimage based on the second difference. The at least one processor mayfurther be configured to cause the system to obtain an exposure value ofthe imaging device and determine the brightness value of the visiblelight of the ambient light based on the first difference, the seconddifference, the G value, the exposure value.

In another aspect of the present disclosure, a method may includeobtaining a first operation mode of the optical filter and determining abrightness value of visible light of ambient light. The ambient lightmay include infrared light and the visible light. The method may alsoinclude obtaining a brightness threshold related to the first operationmode and comparing the brightness value of the visible light of theambient light with the brightness threshold. The method may furtherinclude determining whether a switching condition is satisfied based onthe comparison result. In response to the determination that theswitching condition is satisfied, the method may further includeswitching the first operation mode of the optical filter to a secondoperation mode.

In some embodiments, the method may also include obtaining a first imagecaptured by the imaging device with visible light, a second imagecaptured by the imaging device with infrared light, and a third imagecaptured by the imaging device with the ambient light. The method mayfurther include determining a first difference between the first imageand the second image, a second difference between the second image andthe third image, and a G value related to the third image based on thesecond difference. The method may further include obtaining an exposurevalue of the imaging device and determining the brightness value of thevisible light of the ambient light based on the first difference, thesecond difference, the G value, the exposure value.

In some embodiments, the exposure value of the imaging device mayinclude at least one of a shutter speed, a gain, or an aperture size.

In some embodiments, the first difference between the first image andthe second image may be a Euclidean or Manhattan distance between thefirst image and the second image.

In some embodiments, the second difference between the second image andthe third image may be a Euclidean or a Manhattan distance between thesecond image and the third image.

In some embodiments, the method may also include obtaining a firstplurality of blocks of the first image, RGB data related to each blockof the first plurality of blocks, and a first subset of blocks from thefirst plurality of blocks based on the RGB data related to each block ofthe first plurality of blocks. The method may further includedetermining a first average R/G value and a first average B/G value ofthe first subset of blocks of the first image, obtaining a secondplurality of blocks of the second image; obtaining RGB data related toeach block of the second plurality of blocks, and obtaining a secondsubset of blocks from the second plurality of blocks based on the RGBdata related to each block of second plurality of blocks. The method mayfurther include determining a second average R/G value and a secondaverage B/G value of the second subset of blocks of the second image;and determining the first difference between the first image and thesecond image based on the first average R/G, the first average B/G, thesecond average R/G, and the second average B/G value.

In some embodiments, the method may also include obtaining a thirdplurality of blocks of the third image, RGB data related to each blockof the third plurality of blocks, and a third subset of blocks from thethird plurality of blocks based on the RGB data related to each block ofthe third plurality of blocks. The method may further includedetermining a third average R/G value and a third average B/G value ofthe third subset of blocks of the third image and determining the seconddifference between the second image and the third image based on thesecond average R/G, the second average B/G, the third average R/G, andthe third average B/G value.

In some embodiments, the method may also include obtaining one or morebrightness values of the visible light of the ambient light in a firstperiod. The method may further include determining an average brightnessvalue of the one or more brightness values of the visible light of theambient light and determining the brightness threshold based on theaverage brightness value.

In some embodiments, the first operation mode of the optical filter maybe a day-operation mode or a night-operation mode.

In some embodiments, the first operation mode of the optical filter maybe the night-operation mode. The method may also include obtaining aplurality of brightness values of the visible light of the ambient lightin a second period, and determining a first number of brightness valuesof the visible light of the ambient light exceeding or being equal tothe brightness threshold among the plurality of brightness values of thevisible light of the ambient light in the second period. The method mayfurther include determining whether the first number is equal to orgreater than a first number threshold, and switching the night-operationmode of the optical filter to the day-operation mode in response to thedetermination that the first number is equal to or greater than thefirst number threshold.

In some embodiments, the first operation mode of the optical filter maybe the day-operation mode. The method may also include obtaining aplurality of brightness values of the visible light of the ambient lightin a third period, and determining a second number of brightness valuesof the visible light of the ambient light below the brightness thresholdamong the plurality of brightness values of the visible of the ambientlight in the third period. The method may further include determiningwhether the second number is equal to or greater than a second numberthreshold; and switching the day-operation mode of the optical filter tothe night-operation mode in response to the determination that thesecond number is equal to or greater than the second number threshold.

According to yet another aspect of the present disclosure, anon-transitory machine-readable storage medium storing instructionsthat, when executed by at least one processor of a system, may beconfigured to cause the system to perform a method. The method mayinclude obtaining a first operation mode of the optical filter anddetermining a brightness value of visible light of ambient light, theambient light including infrared light and the visible light. The methodmay also include obtaining a brightness threshold related to the firstoperation mode and comparing the brightness value of the visible lightof the ambient light with the brightness threshold. The method mayfurther include determining whether a switching condition is satisfiedbased on the comparison result. In response to the determination thatthe switching condition is satisfied, the method may further includeswitching the first operation mode of the optical filter to a secondoperation mode.

Additional features will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the artupon examination of the following and the accompanying drawings or maybe learned by production or operation of the examples. The features ofthe present disclosure may be realized and attained by practice or useof various aspects of the methodologies, instrumentalities, andcombinations set forth in the detailed examples discussed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The methods, systems, and/or programming described herein are furtherdescribed in terms of exemplary embodiments. These exemplary embodimentsare described in detail with reference to the drawings. Theseembodiments are non-limiting exemplary embodiments, in which likereference numerals represent similar structures throughout the severalviews of the drawings, and wherein:

FIG. 1 is a schematic diagram of an exemplary image acquisition systemaccording to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary computing device according to someembodiments of the present disclosure;

FIG. 3 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary mobile device according to someembodiments of the present disclosure;

FIG. 4 is a block diagram illustrating an exemplary server according tosome embodiments of the present disclosure;

FIG. 5 is a block diagram illustrating an exemplary processing moduleaccording to some embodiments of the present disclosure;

FIG. 6 is a flowchart of an exemplary process for switching an operationmode of an optical filter according to some embodiments of the presentdisclosure;

FIG. 7 is a flowchart of an exemplary process for determining abrightness value of visible light of ambient light according to someembodiments of the present disclosure;

FIG. 8 is a flowchart of an exemplary process for determining adifference between two images according to some embodiments of thepresent disclosure;

FIG. 9 is a flowchart of an exemplary process for determining abrightness threshold according to some embodiments of the presentdisclosure;

FIG. 10 is a schematic diagram of an exemplary spectrum of infraredlight according to some embodiments of the present disclosure;

FIG. 11 is a schematic diagram of an exemplary image captured by animaging device according to some embodiments of the present disclosure;

FIG. 12 is schematic diagram illustrating a distribution of RGB datacorresponding to the image illustrated in FIG. 11 according to someembodiments of the present disclosure; and

FIG. 13 is schematic diagram illustrating a relationship between a Gvalue of the image of FIG. 11 and a difference between the imageillustrated in FIG. 11 and an image related to infrared light accordingto some embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant disclosure. However, it should be apparent to those skilledin the art that the present disclosure may be practiced without suchdetails. In other instances, well-known methods, procedures, systems,components, and/or circuitry have been described at a relativelyhigh-level, without detail, in order to avoid unnecessarily obscuringaspects of the present disclosure. Various modifications to thedisclosed embodiments will be readily apparent to those skilled in theart, and the general principles defined herein may be applied to otherembodiments and applications without departing from the spirit and scopeof the present disclosure. Thus, the present disclosure is not limitedto the embodiments shown, but to be accorded the widest scope consistentwith the claims.

It will be understood that the term “system,” “engine,” “unit,”“module,” and/or “block” used herein are one method to distinguishdifferent components, elements, parts, section or assembly of differentlevel in ascending order. However, the terms may be displaced by otherexpression if they may achieve the same purpose.

Generally, the word “module,” “unit,” or “block,” as used herein, refersto logic embodied in hardware or firmware, or to a collection ofsoftware instructions. A module, a unit, or a block described herein maybe implemented as software and/or hardware and may be stored in any typeof non-transitory computer-readable medium or other storage device. Insome embodiments, a software module/unit/block may be compiled andlinked into an executable program. It will be appreciated that softwaremodules can be callable from other modules/units/blocks or fromthemselves, and/or may be invoked in response to detected events orinterrupts. Software modules/units/blocks configured for execution oncomputing devices (e.g., processor 201 as illustrated in FIG. 2) may beprovided on a computer readable medium, such as a compact disc, adigital video disc, a flash drive, a magnetic disc, or any othertangible medium, or as a digital download (and can be originally storedin a compressed or installable format that needs installation,decompression, or decryption prior to execution). Such software code maybe stored, partially or fully, on a storage device of the executingcomputing device, for execution by the computing device. Softwareinstructions may be embedded in firmware, such as an EPROM. It will befurther appreciated that hardware modules (or units or blocks) may beincluded in connected logic components, such as gates and flip-flops,and/or can be included in programmable units, such as programmable gatearrays or processors. The modules (or units or blocks) or computingdevice functionality described herein may be implemented as softwaremodules (or units or blocks), but may be represented in hardware orfirmware. In general, the modules (or units or blocks) described hereinrefer to logical modules (or units or blocks) that may be combined withother modules (or units or blocks) or divided into sub-modules (orsub-units or sub-blocks) despite their physical organization or storage.

It will be understood that when a unit, engine, module, or block isreferred to as being “on,” “connected to,” or “coupled to” another unit,engine, module, or block, it may be directly on, connected or coupledto, or communicate with the other unit, engine, module, or block, or anintervening unit, engine, module, or block may be present, unless thecontext clearly indicates otherwise. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

The terminology used herein is for the purposes of describing particularexamples and embodiments only and is not intended to be limiting. Asused herein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “include” and/or“comprise,” when used in this disclosure, specify the presence ofintegers, devices, behaviors, stated features, steps, elements,operations, and/or components, but do not exclude the presence oraddition of one or more other integers, devices, behaviors, features,steps, elements, operations, components, and/or groups thereof.

An optical filter is a widely used component in an imaging device. Theoptical filter may have different operation modes that are suitable fordifferent imaging scenarios. For example, the optical filter may have aday-operation mode and a night-operation mode. The day-operation modemay be suitable for an imaging scenarios with sufficient brightnessvalue. The night-operation mode may be suitable for an imaging scenarioswithout sufficient brightness value. As used herein, “sufficientbrightness value” refers to a brightness value of ambient light in theimaging scenarios is equal to or greater than a brightness threshold.

An aspect of the present disclosure relates to systems and methods forchanging operation modes of an optical filter of an imaging device basedon a brightness value of visible light of ambient light. The ambientlight may be referred herein as to a source of light that may beavailable naturally and not explicitly supplied by a user for takingimages in the imaging scenario. The ambient light may include infraredlight and the visible light. A first operation mode (e.g., an operationmode at the present moment) of an optical filter of an imaging devicemay be obtained. A brightness threshold related to the first operationmode of the optical filter may be obtained. The brightness value of thevisible light of the ambient light may be compared with the brightnessthreshold. A determination whether the comparison result satisfies aswitching condition may be made. In response to the determination thatthe switching condition is satisfied, the first operation mode of theoptical filter may be switched to a second operation mode. As such, theoperation mode of the optical filter may be changed to adapt differentimaging scenarios automatically and efficiently.

FIG. 1 illustrates a schematic diagram of an exemplary image acquisitionsystem according to some embodiments of the present disclosure. Asshown, the image acquisition system 100 may include a server 110, anetwork 120, an image acquisition device 130, a storage device 140, andan optical filter. The image acquisition system 100 may be used invarious fields including, for example, photography, filming, monitoring,and detection.

The server 110 may process information and/or data relating to the imageacquisition system 100 to perform one or more functions described in thepresent disclosure. In some embodiments, the server 110 may include oneor more processing devices (e.g., single-core processing device(s) ormulti-core processor(s)). Merely by way of example, the processingdevice may include a central processing unit (CPU), anapplication-specific integrated circuit (ASIC), an application-specificinstruction-set processor (ASIP), a graphics processing unit (GPU), aphysics processing unit (PPU), a digital signal processor (DSP), a fieldprogrammable gate array (FPGA), a programmable logic device (PLD), acontroller, a microcontroller unit, a reduced instruction-set computer(RISC), a microprocessor, or the like, or any combination thereof.

The server 110 may be a single server or a server group. The servergroup may be centralized, or distributed (e.g., server 110 may be adistributed system). In some embodiments, the server 110 may be local orremote. For example, the server 110 may access information and/or datastored in the image acquisition device 130, and/or the storage device140 via the network 120. As another example, the server 110 may bedirectly connected to the image acquisition device 130, and/or thestorage device 140 to access stored information and/or data. In someembodiments, the server 110 may be implemented on a cloud platform.Merely by way of example, the cloud platform may include a privatecloud, a public cloud, a hybrid cloud, a community cloud, a distributedcloud, an inter-cloud, a multi-cloud, or the like, or any combinationthereof. In some embodiments, the server 110 may be implemented on acomputing device 200 having one or more components illustrated in FIG. 2of the present disclosure.

The network 120 may include any suitable network that can facilitateexchange of information and/or data for the image acquisition system100. In some embodiments, one or more components in the imageacquisition system 100 (e.g., the server 110, the image acquisitiondevice 130, and the storage device 140) may send information and/or datato another component(s) in the image acquisition system 100 via thenetwork 120. For example, the server 110 may obtain/acquire an imagefrom the image acquisition device 130 via the network 120. In someembodiments, the network 120 may be any type of wired or wirelessnetwork, or combination thereof. Merely by way of example, the network120 may include a cable network, a wireline network, an optical fibernetwork, a telecommunications network, an intranet, an Internet, a localarea network (LAN), a wide area network (WAN), a wireless local areanetwork (WLAN), a metropolitan area network (MAN), a wide area network(WAN), a public telephone switched network (PSTN), a Bluetooth network,a ZigBee network, a near field communication (NFC) network, or the like,or any combination thereof.

The image acquisition device 130 may be and/or include any suitabledevice that is capable of acquiring image data. Exemplary imageacquisition device 130 may include a camera (e.g., a digital camera, ananalog camera, an IP camera (IPC), etc.), a video recorder, a scanner, amobile phone, a tablet computing device, a wearable computing device, aninfrared imaging device (e.g., a thermal imaging device), or the like.In some embodiments, the image acquisition device 130 may include a guncamera 130-1, a dome camera 130-2, an integrated camera 130-3, abinocular camera 130-4, a monocular camera, etc. In some embodiments,the camera may be a visible light camera or a thermal imaging camera.

Image data may include an image, or any data about an image, such asvalues of one or more pixels (or referred to as pixel values) of animage (e.g., luma, gray values, intensities, chrominance, contrast ofone or more pixels of an image), RGB data, audio information, timinginformation, location data, etc. In some embodiments, the imageacquisition device 130 may include a charge-coupled device (CCD), acomplementary metal-oxide-semiconductor (CMOS) sensor, an N-typemetal-oxide-semiconductor (NMOS), a contact image sensor (CIS), and/orany other suitable image sensor.

In some embodiments, the image acquisition device 130 may include anoptical filter. For example, the dome camera 130-2 may include anoptical filter 150. For illustration purposes only, only one opticalfilter 150 is labelled in the dome camera 130-2, but other types of theimage acquisition device 130 (e.g., 130-1, 130-3, 130-4) may alsoinclude an optical filter. The optical filter 150 may selectivelytransmit light of different wavelengths. The optical filter 150 may bean infrared cut-off optical filter, a monochromatic optical filter, adichroic optical filter, a metal mesh optical filter, an all-passoptical filter, or the like, or any combination thereof. Different typesof optical filters may have different transmission characteristics oflight. For example, the infrared cut-off optical filter may cut offinfrared light and transmit visible light. The all-pass optical filtermay transmit any types of light, such as radio light, microwave light,infrared light, visible light, ultraviolet light, X-rays.

In some embodiments, the optical filter 150 may include one or moretypes of optical filters. A type of the optical filters may correspondto an operation mode of the optical filter 150. Exemplary operationmodes of optical filter 150 may include a day-operation mode, anight-operation mode, an indoor-operation mode, or outdoor-operationmode, or the like, or any combination thereof. When operating indifferent operation modes, the optical filter 150 may have differenttransmission characteristics of light. For example, in the infraredcut-off operation mode, the optical filter may cut off infrared lightand transmit visible light. The operation mode of the optical filter 150may be set manually or be determined by one or more components of theimage acquisition system 100 (e.g., the server 110). Merely by way ofexample, the operation mode of optical filter 150 may be switched by auser via the image acquisition device 130. As another example, theoperation mode of optical filter 150 may be determined by the server 110based on the imaging scenarios (e.g., a brightness value of visiblelight of ambient light) when taking an image.

In some embodiments, the image acquisition device 130 may include aprocessing device (not shown in FIG. 1). The processing device mayprocess information and/or data relating to the image acquisition device130 to perform one or more functions described in the presentdisclosure. In some embodiments, the processing device may beimplemented on a computing device 200 having one or more componentsillustrated in FIG. 2 of the present disclosure.

In some embodiments, the image data acquired by the image acquisitiondevice 130 may be displayed on a terminal (not shown in FIG. 1). Theterminal may include a tablet computer, a laptop computer, a mobilephone, a personal digital assistance (PDA), a smart watch, a point ofsale (POS) device, a virtual reality (VR), an augmented reality (AR), anonboard computer, an onboard television, a wearable device, or the like,or any combination thereof.

The storage device 140 may store data and/or instructions. The dataand/or instructions may be obtained from, for example, the server 110,the image acquisition device 130, and/or any other component of theimage acquisition system 100.

In some embodiments, the storage device 140 may store data and/orinstructions that the server 110 may execute or use to perform exemplarymethods described in the present disclosure. In some embodiments,storage device 140 may include a mass storage, a removable storage, avolatile read-and-write memory, a read-only memory (ROM), or the like,or any combination thereof. Exemplary mass storage may include amagnetic disk, an optical disk, a solid-state drives, etc. Exemplaryremovable storage may include a flash drive, a floppy disk, an opticaldisk, a memory card, a zip disk, a magnetic tape, etc. Exemplaryvolatile read-and-write memory may include a random access memory (RAM).Exemplary RAM may include a dynamic RAM (DRAM), a double date ratesynchronous dynamic RAM (DDR SDRAM), a static RAM (SRAM), a thyristorRAM (T-RAM), and a zero-capacitor RAM (Z-RAM), etc. Exemplary ROM mayinclude a mask ROM (MROM), a programmable ROM (PROM), an erasableprogrammable ROM (PEROM), an electrically erasable programmable ROM(EEPROM), a compact disk ROM (CD-ROM), and a digital versatile disk ROM,etc. In some embodiments, the storage device 140 may be implemented on acloud platform. Merely by way of example, the cloud platform may includea private cloud, a public cloud, a hybrid cloud, a community cloud, adistributed cloud, an inter-cloud, a multi-cloud, or the like, or anycombination thereof.

In some embodiments, the storage device 140 may be connected to thenetwork 120 to communicate with one or more components of the imageacquisition system 100 (e.g., the server 110, the image acquisitiondevice 130, etc.). One or more components of the image acquisitionsystem 100 may access the data or instructions stored in the storagedevice 140 via the network 120. In some embodiments, the storage device140 may be directly connected to or communicate with one or morecomponents of the image acquisition system 100 (e.g., the server 110,the image acquisition device 130, etc.). In some embodiments, thestorage device 140 may be part of the server 110 or the imageacquisition device 130.

In some embodiments, one or more components of the image acquisitionsystem 100 (e.g., the server 110, the image acquisition device 130,etc.) may have a permission to access the storage device 140. In someembodiments, one or more components of the image acquisition system 100may read and/or modify information relating to the image when one ormore conditions are met. For example, the server 110 or the imageacquisition device 130 may read and/or modify operation modes of theoptical filter 150 in various application scenario.

It should be noted that the above description is merely provided for thepurposes of illustration, and not intended to limit the scope of thepresent disclosure. For persons having ordinary skills in the art,multiple variations and modifications may be made under the teachings ofthe present disclosure. For example, the image acquisition system 100may include one or more terminals. As another example, the processingdevice may be integrated into the image acquisition device 130. However,those variations and modifications do not depart from the scope of thepresent disclosure.

FIG. 2 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary computing device 200 on which theserver 110 may be implemented according to some embodiments of thepresent disclosure. As illustrated in FIG. 2, the computing device 200may include a processor 201, a storage 203, an input/output (I/O) 205,and a communication port 207.

The processor 201 may execute computer instructions (e.g., program code)and perform functions of the image acquisition system 100 in accordancewith techniques as described elsewhere in the present disclosure. Thecomputer instructions may include, for example, routines, programs,objects, components, data structures, procedures, modules, andfunctions, which perform particular functions as described elsewhere inthe present disclosure. For example, the processor 201 may determine oneor more exposure values of the image acquisition device 130. In someembodiments, the processor 201 may include one or more hardwareprocessors, such as a microcontroller, a microprocessor, a reducedinstruction set computer (RISC), an application specific integratedcircuits (ASICs), an application-specific instruction-set processor(ASIP), a central processing unit (CPU), a graphics processing unit(GPU), a physics processing unit (PPU), a microcontroller unit, adigital signal processor (DSP), a field-programmable gate array (FPGA),an advanced RISC machine (ARM), a programmable logic device (PLD), anycircuit or processor capable of executing one or more functions, or thelike, or any combinations thereof.

Merely for illustration, only one processor may be described in thecomputing device 200. However, it should be noted that the computingdevice 200 of the present disclosure may also include multipleprocessors, and thus operations and/or method steps that are performedby one processor as described in the present disclosure may also bejointly or separately performed by the multiple processors. For example,if in the present disclosure the processor of the computing device 200executes both operations A and operation B, it should be understood thatoperation A and operation B may also be performed by two or moredifferent processors jointly or separately in the computing device 200(e.g., a first processor executes operation A and a second processorexecutes operation B, or vice versa, or the first and second processorsjointly execute operations A and B).

The storage 203 may store data/information obtained from the server 110,the image acquisition device 130, and/or any other component of theimage acquisition system 100. In some embodiments, the storage 203 mayinclude a mass storage, removable storage, a volatile read-and-writememory, a read-only memory (ROM), or the like, or any combinationthereof. For example, the mass storage may include a magnetic disk, anoptical disk, solid-state drives, etc. The removable storage may includea flash drive, a floppy disk, an optical disk, a memory card, a zipdisk, a magnetic tape, etc. The volatile read-and-write memory mayinclude a random access memory (RAM). The RAM may include a dynamic RAM(DRAM), a double date rate synchronous dynamic RAM (DDR SDRAM), a staticRAM (SRAM), a thyristor RAM (T-RAM), and a zero-capacitor RAM (Z-RAM),etc. The ROM may include a mask ROM (MROM), a programmable ROM (PROM),an erasable programmable ROM (EPROM), an electrically-erasableprogrammable ROM (EEPROM), a compact disk ROM (CD-ROM), and a digitalversatile disk ROM, etc. In some embodiments, the storage 203 may storeone or more programs and/or instructions to perform exemplary methodsdescribed in the present disclosure. For example, the storage 203 maystore a program for switching operation modes of an optical filter ofthe image acquisition device 130.

The I/O 205 may input and/or output signals, data, information, etc. Insome embodiments, the I/O 205 may enable a user interaction with theprocessing device. In some embodiments, the I/O 205 may include orcommunicate with an input device and an output device to facilitatecommunication between the processing device and an input device or anoutput device. Examples of the input device may include a keyboard, amouse, a touch screen, a microphone, or the like, or any combinationthereof. Examples of the output device may include a display device, aloudspeaker, a printer, a projector, or the like, or any combinationthereof. Examples of the display device may include a liquid crystaldisplay (LCD), a light-emitting diode (LED)-based display, a flat paneldisplay, a curved screen, a television device, a cathode ray tube (CRT),a touch screen, or the like, or any combination thereof.

The communication port 207 may be connected to a network (e.g., thenetwork 120) to facilitate data communications. The communication port207 may establish connections between the server 110, the imageacquisition device 130, and/or any other component of the imageacquisition system 100. The connection may be a wired connection, awireless connection, any other communication connection that can enabledata transmission and/or reception, and/or any combination of theseconnections. The wired connection may include, for example, anelectrical cable, an optical cable, a telephone wire, or the like, orany combination thereof. The wireless connection may include, forexample, a Bluetooth™ link, a Wi-Fi™ link, a WiMax™ link, a WLAN link, aZigBee link, a mobile network link (e.g., 3G, 4G, 5G, etc.), or thelike, or any combination thereof. In some embodiments, the communicationport 207 may be and/or include a standardized communication port, suchas RS232, RS485, etc. In some embodiments, the communication port 207may be a specially designed communication port. For example, thecommunication port 207 may be designed in accordance with the digitalimaging and communications in medicine (DICOM) protocol.

FIG. 3 is a schematic diagram illustrating exemplary hardware and/orsoftware components of an exemplary mobile device 300 on which the imageacquisition device 130 may be implemented according to some embodimentsof the present disclosure. As illustrated in FIG. 3, the mobile device300 may include a communication port 310, a display 320, a graphicprocessing unit (GPU) 330, a central processing unit (CPU) 340, an I/O350, a memory 360, and a storage 390. In some embodiments, any othersuitable component, including but not limited to a system bus or acontroller (not shown), may also be included in the mobile device 300.In some embodiments, a mobile operating system 370 (e.g., iOS™,Android™, Windows Phone™, etc.) and one or more applications 380 may beloaded into the memory 360 from the storage 390 in order to be executedby the CPU 340. The applications 380 may include a browser or any othersuitable mobile apps for receiving and rendering information relating toimage processing or other information from the processing device. Userinteractions with the information stream may be achieved via the I/O 350and provided to the processing device and/or other components of theimage acquisition system 100 via the network 120.

To implement various modules, units, and their functionalities describedin the present disclosure, computer hardware platforms may be used asthe hardware platform(s) for one or more of the elements describedherein. A computer with user interface elements may be used to implementa personal computer (PC) or any other type of work station or terminaldevice. A computer may also act as a server if appropriately programmed.

FIG. 4 is a block diagram illustrating an exemplary server 110 accordingto some embodiments of the present disclosure. The server 110 mayinclude an acquisition module 410, a control module 420, a storagemodule 430, and a processing module 440. At least two components of theserver 110 may be connected to or communicated with each other and/orother components of the image acquisition system 100, for example, thestorage 140. In some embodiments, the server 110 may be implemented onthe computing device 200 illustrated in FIG. 2.

Generally, the terms “module,” “unit,” and/or “engine” used herein,refers to logic embodied in hardware or firmware, or to a collection ofsoftware instructions. The modules, units, and engines described hereinmay be implemented as software and/or hardware modules and may be storedin any type of non-transitory computer-readable medium or other storagedevice. In some embodiments, a software module may be compiled andlinked into an executable program. It will be appreciated that softwaremodules can be callable from other modules or from themselves, and/orcan be invoked in response to detected events or interrupts. Softwaremodules configured for execution on computing devices (e.g., processor201 or CPU 340) can be provided on a computer readable medium, such as acompact disc, a digital video disc, a flash drive, a magnetic disc, orany other tangible medium, or as a digital download (and can beoriginally stored in a compressed or installable format that requiresinstallation, decompression, or decryption prior to execution). Suchsoftware code can be stored, partially or fully, on a memory device ofthe executing computing device, for execution by the computing device.Software instructions can be embedded in a firmware, such as an EPROM.It will be further appreciated that hardware modules can be included ofconnected logic units, such as gates and flip-flops, and/or can beincluded of programmable units, such as programmable gate arrays orprocessors. The modules or computing device functionality describedherein are preferably implemented as software modules, but can berepresented in hardware or firmware. In general, the modules describedherein refer to logical modules that can be combined with other modulesor divided into sub-modules despite their physical organization orstorage.

The acquisition module 410 may acquire data and/or an instructionrelated to the image acquisition system 100. The data and/or theinstruction may include one or more images captured by the imageacquisition device 130, operation information of the image acquisitiondevice 130, an instruction input by a user via the image acquisitiondevice 130, or the like, or any combination thereof. The data orinstruction may be acquired from other components of the imageacquisition system 100 (e.g., retrieved from the storage 140 or theimage acquisition device 130 via the network 120) or generated by othercomponents in the server 110 (e.g., the processing module 440).

The control module 420 may control operations of one or more componentsof the image acquisition system 100, such as the acquisition module 410,the storage module 430, and/or the processing module 440 (e.g., bygenerating one or more control parameters). For example, the controlmodule 420 may control the acquisition module 410 to acquire image dataor a set of instructions, etc. As another example, the control module420 may control the processing module 440 to process image data acquiredby the acquisition module 410. In some embodiments, the control module420 may receive a real-time command or retrieve a predetermined commandprovided by a user (e.g., a photographer) to control one or moreoperations of the acquisition module 410 and/or the processing module440. For example, the control module 420 can adjust the acquisitionmodule 410 and/or the processing module 440 to generate images of asubject according to the real-time command and/or the predeterminedcommand. In some embodiments, the control module 420 may communicatewith one or more other modules of the server 110 for exchanginginformation and/or data.

The storage module 430 may store image data, exposure value, a real-timecommand or retrieve a predetermined command provided by a user, or thelike, or a combination thereof. In some embodiments, the storage 430 maystore one or more programs and/or instructions that may be executed bythe processor(s) of the processing engine to perform exemplary methodsdescribed in this disclosure. For example, the storage 430 may storeprogram(s) and/or instruction(s) that can be executed by theprocessor(s) of the processing engine to acquire operation modes of anoptical filter of an imaging device.

The processing module 440 may process information provided by variousmodules of the server 110. For example, the processing module 440 mayprocess image data acquired by the acquisition module 410 and/or imagedata retrieved from the storage module 430.

In some embodiments, one or more modules illustrated in FIG. 4 may beimplemented in at least part of the exemplary image acquisition system100 as illustrated in FIG. 1. For example, the one or more modules ofthe server 110 may be integrated into a processing device. As anotherexample, one or more modules of the server 110 may be integrated intothe image acquisition device 130.

It should be noted that the above descriptions of the server 110 aremerely provided for the purposes of illustration, and not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, various modifications and changes in the forms anddetails of the application of the above method and system may occurwithout departing from the principles of the present disclosure. Forexample, the acquisition module 410 and the processing module 440 mayform a module to acquire and process data related to the imageacquisition system 100. However, those variations and modifications alsofall within the scope of the present disclosure.

FIG. 5 is a block diagram illustrating an exemplary processing module440 according to some embodiments of the present disclosure. Theprocessing module 440 may include an acquisition unit 510, adetermination unit 520, a comparison unit 530, and a control unit 540.The processing module 440 may be implemented on various components(e.g., the processor 210 of the computing device 200 as illustrated inFIG. 2).

The acquisition unit 510 may obtain data related to the imageacquisition system 100 (e.g., data related to an imaging device of theimage acquisition system 100). For example, the acquisition unit 510 mayobtain data related to the optical filter 150 of an imaging device. Thedata related to the optical filter 150 may include an operation mode,operation information, a brightness threshold related to an operationmode of the optical filter 150, or the like, or any combination thereof.

As another example, the acquisition unit 510 may obtain image datarelated to the imaging device. The image data may include one or moreimages captured by the imaging device, RGB data of the images capturedby the imaging device, or the like, or any combination thereof.Additionally or alternatively, the acquisition unit 510 may obtain aplurality of blocks of the images captured by the imaging device and/orimage data related to the blocks of the images. More descriptionsregarding the data related to acquisition system 100 may be foundelsewhere in the present disclosure (e.g., FIGS. 6 to 8 and the relevantdescriptions).

The determination unit 520 may determine one or more values related tothe image acquisition system 100. The one or more values may include abrightness value of visible light of ambient light, a brightnessthreshold related to an operation mode of the optical filter 150, adifference between two images, or the like, or any combination thereof.More descriptions regarding determination of the values related to theimaging acquisition system 100 may be found elsewhere of the presentdisclosure (e.g., FIGS. 6 to 9 and the relevant descriptions).

Additionally or alternatively, the determination unit 520 may determinewhether a switching condition of the optical filter 150 is satisfiedbased on a comparison result generated by the comparison unit 530. Theswitching condition may be a default condition stored in a storagedevice (e.g., the storage device 140) or be set by a user of the imagingdevice. Upon the determination that the switching condition issatisfied, the determination unit 520 may transmit an instruction to thecontrol module 540 to switch the operation mode of the optical filter150.

The comparison unit 530 may make comparison between two values and/orgenerate a comparison result. For example, the comparison unit 530 maycompare a brightness value of visible light of ambient light with abrightness threshold to generate a comparison result. In someembodiments, the comparison result may be a difference between thebrightness value of the visible light of the ambient and the brightnessthreshold.

The control unit 540 may control the operation mode of the opticalfilter 150 of an imaging device. For example, the optical filter 150 mayoperate in a day-operation mode, and the control unit 540 may switch theoptical filter 150 from the day-operation mode to a night-operationmode. As another example, the optical filter 150 may operate in thenight-operation mode, and the control unit 540 may switch the opticalfilter 150 from the night-operation mode to the day-operation mode. Insome embodiments, the comparison unit 540 may control the optical filter150 to change its operation mode if a switch condition is satisfied.

It should be noted that the above descriptions of FIGS. 4 to 5 areprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, various modifications and changes in the forms and details ofthe application of the above method and system may occur withoutdeparting from the principles of the present disclosure.

In some embodiments, the server 110 and/or the processing module 440 mayinclude one or more other modules. For example, the server 110 mayinclude a storage module to store data generated by the modules in theserver 110. In some embodiments, one or more modules of the server 110and/or the processing module 440 may be omitted. In some embodiments,one module may perform the functions of two or more modules describedabove. However, those variations and modifications also fall within thescope of the present disclosure.

FIG. 6 is a flowchart of an exemplary process for switching an operationmode of an optical filter according to some embodiments of the presentdisclosure. In some embodiments, at least part of process 600 may beperformed by the server 110 (implemented in, for example, the processor201 of the computing device 200 shown in FIG. 2).

In 602, the acquisition unit 510 may obtain a first operation mode ofthe optical filter 150 of an imaging device. The imaging device may bethe image acquisition device 130 (e.g., a gun camera 130-1, a domecamera 130-2, an integrated camera 130-3, a binocular camera 130-4, amonocular camera, etc.) described in connection with FIG. 1. The opticalfilter 150 may selectively transmit light of different wavelengths. Theoptical filter 150 may be an infrared cut-off optical filter, amonochromatic optical filter, a dichroic optical filter, a metal meshoptical filter, an all-pass optical filter, or the like, or anycombination thereof. Different types of optical filters may havedifferent transmission characteristics of light. For example, theinfrared cut-off optical filter may cut off the infrared light andtransmit visible light. The visible light may be light whose wavelengthis in a range of 400 nm to 700 nm. The infrared light may be light whosewavelength is in a range of 700 nm to 1000 nm (as an example illustratedin FIG. 10). The all-pass optical filter may transmit any types oflight, such as radio light, microwave light, infrared light, visiblelight, ultraviolet light, X-rays light and rays.

In some embodiments, the optical filter 150 may include at least twotypes of optical filters. A type of the optical filter may correspond toan operation mode of the optical filter 150. For example, the at leasttwo types of optical filters may be the infrared cut-off optical filterand the all-pass optical filter. The optical filter 150 may have twocorresponding operation modes; that is, the infrared cut-off operationmode and the all-pass operation mode.

The imaging device may capture an image in an imaging scenario underambient light. The ambient light herein refers to a source of light thatmay be available naturally and not explicitly supplied by a user for thepurpose of taking images in the imaging scenario. The ambient light mayinclude infrared light and visible light.

The quality of the image captured by the imaging device may beassociated with a brightness value of the ambient light. The brightnessvalue of the ambient light may be associated with a brightness value ofthe visible light and a brightness value of the infrared light. In thedaytime, the brightness of the visible light of the ambient light issufficient for the imaging device to obtain an image with a high ordesirable quality (e.g., the brightness of the image being equal to orgreater than a threshold). The optical filter 150 may operate in theinfrared cut-off operation mode to cut off the infrared light in theambient light. At night, the brightness of the visible light of theambient light may not be sufficient for the imaging device to obtain theimage with high or describable quality. The optical filter 150 mayoperate in the all-pass operation mode to transmit the visible light andthe infrared light in the ambient light. Accordingly, the infraredcut-off operation mode may also be referred herein as a day-operationmode, and the all-pass operation mode may also be referred herein as anight-operation mode.

In some embodiments, the first operation mode may be the operation modeof the optical filter 150 at the present moment or at a defined timereasonably close to the present moment. The acquisition unit 510 mayobtain and/or determine the first operation mode of the optical filter150 according to operation information of the optical filter 150. Theoperation information may include the information related to theoperation mode of the optical filter 150 at the present moment or at thedefined time reasonably close to the present moment. The acquisitionunit 510 may obtain the operation information of the optical filter 150from a component of the image acquisition system 100, such as thestorage device 140, the image acquisition device 130, or the storagemodule 430.

In 604, the determination unit 520 may determine a brightness value ofvisible light of ambient light. In some embodiments, the determinationunit 520 may determine the brightness value of the visible light of theambient light based on one or more images captured by the imaging deviceunder the first operation mode of the optical filter 150 and one or moreexposure values of the imaging device. More descriptions regarding thedetermination of the brightness value of the visible light of theambient light may be found elsewhere of the present disclosure (e.g.,FIG. 7 and the relevant descriptions).

In 606, the acquisition unit 510 may obtain a brightness thresholdrelated to the first operation mode. In some embodiments, the brightnessthreshold related to the first operation mode may be a default parameterstored in a storage device (e.g., the storage device 140) or a parameterset by a user of the imaging device. Additionally or alternatively, thebrightness threshold may be determined by one or more components (e.g.,the determination unit 520) of the image acquisition system 100.

In some embodiments, the determination unit 520 may determine thebrightness threshold based on one or more brightness values of thevisible light of the ambient light in a period. For example, thebrightness threshold may be a threshold determined according to the oneor more brightness values in the period, such as an average value of theone or more brightness values, a median value of the one or morebrightness values, a ratio of the average value of the one or morebrightness values. In some embodiments, the brightness threshold may bedetermined according to one or more operations in process 900 (e.g.,FIG. 9 and the relevant descriptions).

The first operation mode of the optical filter 150 may be theday-operation mode, the night-operation mode, or the like described inconnection with step 602. The brightness thresholds related to differentoperation modes may be the same as or different from each other. Thedetermination of the brightness thresholds related to different modesmay be the same as or different from each other.

Merely by way of example, the brightness threshold related to thenight-operation mode may be a default parameter retrieved by theacquisition unit 510 from the storage device 140. The brightnessthreshold related to the day-operation mode may be a thresholddetermined by the determination unit 520. As another example, thebrightness threshold related to the night-operation mode or theday-operation mode may be thresholds determined by the determinationunit 520 according to one or more operations in process 900 (e.g., FIG.9 and the relevant descriptions).

In 608, the comparison unit 530 may compare the brightness value of thevisible light of the ambient light with the brightness threshold togenerate a comparison result. For example, the comparison unit 530 maycompare the numerical values of the brightness value with the brightnessthreshold. In some embodiments, the comparison unit 530 may determine adifference between the brightness value and the brightness threshold.The comparison unit 530 may designate the determined difference as aresult of the comparison.

In some embodiments, in 604, the determination unit 520 may obtain aplurality of brightness values of the visible light of the ambient lightin a period. The comparison unit 530 may compare each of the pluralityof brightness values of the visible light of the ambient light with thebrightness threshold to generate the comparison result. For example,when the first operation mode of the optical filter 150 is thenight-operation mode, the comparison unit 530 may obtain a first numberof brightness values of the visible light of the ambient light of theplurality of brightness values exceeding or being equal to thebrightness threshold. The comparison unit 530 may also designate thefirst number as the comparison result.

When the first operation mode of the optical filter 150 is theday-operation mode, the comparison unit 530 may obtain a second numberof brightness values of the visible light of the ambient light of theplurality of brightness values below the brightness threshold. Thecomparison unit 530 may also designate the second number as thecomparison result.

In 610, the determination unit 520 may determine whether a switchingcondition is satisfied based on the comparison result. The switchingcondition may be a default condition stored in a storage device (e.g.,the storage device 140) or be set by a user of the imaging device. Uponthe determination that the switching condition is satisfied, the process600 may proceed to 612. On the other hand, upon the determination thatthe switching condition is not satisfied, the process 600 may proceed to604, and steps 604 to 608 may be performed.

The switching condition may include a switching threshold associatedwith the comparison result. For example, the comparison result may bethe difference between the brightness value and the brightness thresholddescribed in connection with 608. The switching condition may be whetherthe difference between the brightness value and the brightness thresholdis equal to or greater than a difference threshold.

For instance, the determination unit 520 may determine whether thedifference between the brightness value and the brightness threshold isequal to or greater than a difference threshold. Upon the determinationthat the difference between the brightness value and the brightnessthreshold is equal to or greater than the difference threshold, theprocess 600 may proceed to 612. On the other hand, upon thedetermination that the difference between the brightness value and thebrightness threshold is smaller than the difference threshold, theprocess 600 may proceed to 604, and steps 604 to 608 may be performed.

As another example, if the first operation mode is the night-operationmode, the comparison result may be the first number of brightness valuesof the visible light of the ambient light of the plurality of brightnessvalues exceeding or being equal to the brightness threshold. Theswitching condition may be whether the first number is equal to orgreater than a first number threshold. As yet another example, if thefirst operation mode is the day-operation mode, the comparison resultmay be the second number of brightness values of the visible light ofthe ambient light of the plurality of brightness values below thebrightness threshold. The switching condition may be whether the secondnumber is equal to or greater than a second number threshold. The firstnumber threshold or the second number threshold may be a defaultparameter stored in a storage device (e.g., the storage device 140) or aparameter set by a user of the imaging device.

In 612, the control unit 540 may switch the first operation mode of theoptical filter 150 to a second operation mode. Merely by way of example,the first operation mode may be the night-operation mode and the secondoperation mode may be the day-operation mode. Upon the determinationthat the switching condition is satisfied, the control unit 540 mayswitch the night-operation mode to the day-operation mode.

Alternatively, the first operation mode may be the day-operation modeand the second operation mode may be the night-operation. Upon thedetermination that the switching condition is satisfied, the controlunit 540 may switch the day-operation mode to the night-operation mode.

It should be noted that the above descriptions of the process 600 areprovided for the purposes of illustration and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, various modifications and changes in the forms and details ofthe application of the above method and system may occur withoutdeparting from the principles of the present disclosure. However, thosevariations and modifications also fall within the scope of the presentdisclosure.

In some embodiments, the order of the operations in process 600 may bechanged. For example, 602 and 606 may be performed simultaneously. Asanother example, 606 may be performed before 604. In some embodiments,in 604, the determination unit 520 may determine a plurality ofbrightness value of visible light of ambient light. In 604, thedetermination unit 520 may determine the brightness threshold related tothe first operation mode by performing one or more operations of process900 illustrated in FIG. 9.

In some embodiments, if the first operation mode is the day-operationmode, the determination unit 520 may determine the brightness value ofthe visible light of the ambient light based on an image captured by theimaging device in the day-operation mode. The brightness value of thevisible light may be equal to a brightness value of the image taken inthe day-operation mode. The brightness threshold of related to theday-operation mode may be a default parameter stored in a storage device(e.g., the storage device 140) or a parameter set by a user of theimaging device.

In some embodiments, the brightness value of an image may be determinedby the determination module 520 according to the RGB data of the image.For example, the determination module 520 may assign the R value, the Gvalue, or the B value of the image as the brightness value of the image.Alternatively or additionally, the determination module 520 may convertthe RGB data of the image to Luminance-Bandwidth-Chrominance (YUV) data,and determine the brightness value of the image based on the YUV data.For instance, the determination module 520 may assign the luma (i.e., Y)value as the brightness value of the image.

Additionally or alternatively, the brightness value of the visible lightmay be a value determined based on brightness values of a plurality ofimages taken in the day-operation mode. The plurality of images may becaptured by the imaging device in a predetermined time frame, such as inevery 2 seconds. The brightness value of the visible light may be equalto an average brightness value, a median brightness value or any othervalues determined based on the brightness values of the plurality ofimages.

The brightness threshold related to the night-operation mode may bedetermined based on the image taken in the day-operation mode, thebrightness threshold related to the day-operation mode, and an imagetaken in the night-operation mode, as described in Equation (1) below:

Threshold₁ =Lu ₂+(Threshold₀ −Lu ₁)*α+ε  Equation (1),

where Threshold₁ refers to the brightness threshold related tonight-operation mode, Threshold₀ refers to the brightness thresholdrelated to day-operation mode, Lu₂ refers to a brightness value of theimage captured by the imaging device in the night-operation mode, Lu₁refers to the brightness value of the image captured by the imagingdevice in the day-operation mode, and a refers to a sum of 1 and a ratioof a brightness value of infrared light and a brightness of visiblelight. E refers to a tolerance value of the brightness, which may be anysuitable positive value.

FIG. 7 is a flowchart of an exemplary process for determining abrightness value of visible light of ambient light of an imaging deviceaccording to some embodiments of the present disclosure. In someembodiments, at least part of process 700 may be performed by the server110 (implemented in, for example, the processor 201 of the computingdevice 200). In some embodiments, step 606 of the process 600 may beperformed according to the process 700. In some embodiments, the imagingdevice may operate process 700 in the first operation mode, such as thenight-operation mode, the day-operation mode described in connectionwith FIG. 6.

In 702, the acquisition unit 510 may obtain a first image captured bythe imaging device with visible light. In some embodiments, the firstimage may be captured by the imaging device in an experimentalenvironment only including visible light or reasonably close to onlyincluding a visible light. For example, the imaging device may be put inan enclosed space (e.g., a lamp house) with a visible light source(e.g., a fluorescent lamp). A gray plate may be put in front of theimaging device. In some embodiments, the first image may be captured bythe imaging device and stored in a storage device (e.g., the storagedevice 140, the storage module 430). The acquisition unit 510 may obtainthe first image from the storage device.

In 704, the acquisition unit 510 may obtain a second image captured bythe imaging device with infrared light. In some embodiments, the secondimage may be captured by the imaging device in an experimentalenvironment only including infrared light or reasonably close to onlyincluding an infrared light. For example, the imaging device may be putin a space without a visible light source (e.g., a fluorescent lamp) andhaving an infrared light source (e.g., infrared light). A gray plate maybe put in front of the imaging device. In some embodiments, the secondimage may be captured by the imaging device and stored in storage device(e.g., the storage device 140, the storage module 430). The acquisitionunit 510 may obtain the second image from the storage device.

In 706, the acquisition unit 510 may obtain a third image captured bythe imaging device with ambient light. In some embodiments, the thirdimage may be captured by the imaging device in a natural environmentwithout light source explicitly supplied. In some embodiments, the thirdimage may be captured by the imaging device and stored in storage device(e.g., the storage device 140, the storage module 430). The acquisitionunit 510 may obtain the third image from the storage device.

The ambient light may include visible light and infrared light. Thevisible light and the infrared light may be described by RGB data. RGBis a color model including red, green, and blue color. The RGB data mayinclude an R value, a G value, and/or a B value. The R value, the Gvalue, and the B value may correspond to a value of red, a value ofgreen, and a value of blue, respectively. The R value, the G value, andthe B value may be any positive number between 0 and 255. The RGB datamay be described as (R, G, B). For example, the RGB data correspondingto red may be (255, 0, 0). For illustration purposes, the RGB data ofthe visible light may be denoted as A (Ra, Ga, Ba), and the RGB data ofthe infrared light may be denoted as B (Rb, Gb, Bb). The RGB data of theambient light including the visible light and the infrared light may bedenoted as C (Rc, Gc, Bc). In some embodiments, the C (Rc, Gc, Bc) maybe determined based on the RGB data of the visible light, the RGB dataof infrared light, and proportions of the visible light and the infraredlight in the ambient light according to Equation (2) or Equation (3) asbelow:

(R _(c) ,G _(c) ,B _(c))=(R _(a) ,G _(a) ,B _(a))+k ₁*(R _(b) ,G _(b) ,B_(b))  Equation (2),

(R _(c) ,G _(c) ,B _(c))=k ₂(R _(a) ,G _(a) ,B _(a))+k ₃*(R _(b) ,G _(b),B _(b))  Equation (3),

where k₂ refers to a proportion of the visible light in the ambientlight, k₃ refers to a proportion of the infrared light in the ambientlight, and k₁ refers to a ratio of the proportion of the visible lightover the proportion of the infrared light in the ambient light.

In 708, the determination unit 520 may determine a first differencebetween the first image and the second image. In some embodiments, thefirst difference between the first image and the second image may be aEuclidean or Manhattan distance between the first image and the secondimage. The first difference may be determined based on the process 800described elsewhere in this disclosure (e.g., FIG. 8 and the relevantdescriptions).

In 710, the determination unit 520 may determine a second differencebetween the second image and the third image. In some embodiments, thesecond difference between the third image and the second image may be aEuclidean or Manhattan distance between the third image and the secondimage. The second difference may be determined based on the process 800described elsewhere in this disclosure (e.g., FIG. 8 and the relevantdescriptions).

In 712, the determination unit 520 may determine a G value related tothe third image based on the second difference and the first difference.The G value of the third image associated with the ambient light may bedenoted as Gc, which refers to the value of green of the ambient light.In some embodiments, the RGB data of the ambient light may be determinedaccording to Equation (2). The first difference may be a first Euclideandistance between the first image and the second image. The seconddifference may be a second Euclidean distance between the second imageand the third image. The relationship between the G value of the thirdimage and the second Euclidean distance between the second image and thethird image may be described according to Equations (4) as below:

                                     Equation  (4)${{G_{c}*x} = {{G_{c}\sqrt{\left( {\frac{R_{c}}{G_{c}} - \frac{R_{b}}{G_{b}}} \right)^{2} + \left( {\frac{B_{c}}{G_{c}} - \frac{B_{b}}{G_{b}}} \right)^{2}}} = {\sqrt{{G_{c}^{2}\left( {\frac{R_{c}}{G_{c}} - \frac{R_{b}}{G_{b}}} \right)}^{2} + {G_{c}^{2}\left( {\frac{B_{c}}{G_{c}} - \frac{B_{b}}{G_{b}}} \right)}^{2}} = {\sqrt{\left( {R_{c} - \frac{G_{c}R_{b}}{G_{b}}} \right)^{2} + \left( {B_{c} - \frac{G_{c}B_{b}}{G_{b}}} \right)^{2}} = {\sqrt{\left( {R_{a} + {kR}_{b} - \frac{\left( {G_{a} + {k\; G_{b}}} \right)R_{b}}{G_{b}}} \right)^{2} + \left( {B_{a} + {k\; B_{b}} - \frac{\left( {G_{a} + {k\; G_{b}}} \right)B_{b}}{G_{b}}} \right)^{2}} = {\sqrt{\left( {R_{a} + {kR}_{b} - \frac{G_{a}R_{b}}{G_{b}} - {k\; R_{b}}} \right)^{2} + \left( {B_{a} + {k\; B_{b}} - \frac{G_{a}\; B_{b}}{G_{b}} - {k\; B_{b}}} \right)^{2}} = {\sqrt{\left( {R_{a} - {G_{a}\frac{R_{b}}{G_{b}}}} \right)^{2} + \left( {B_{a} - {G_{a}\frac{B_{b}}{G_{b}}}} \right)^{2}} = {{G_{a}\sqrt{\left( {\frac{R_{a}}{G_{a}} - \frac{R_{b}}{G_{b}}} \right)^{2} + \left( {\frac{B_{a}}{G_{a}} - \frac{B_{b}}{G_{b}}} \right)^{2}}} = d}}}}}}}},$

where x refers to the second Euclidean distance between the second imageand the third image (will be described in FIG. 8), d refers to a productof the G value of the third image and the second distance, and

$\sqrt{\left( {\frac{R_{a}}{G_{a}} - \frac{R_{b}}{G_{b}}} \right)^{2} + \left( {\frac{B_{a}}{G_{a}} - \frac{B_{b}}{G_{b}}} \right)^{2}}$

refers to the first Euclidean distance between the first image and thesecond image.

According to Equation (4), the product of the G value of the third imageand the second Euclidean distance between the second image and the thirdimage; that is, d may be a constant. The G value of the third image maybe determined according to Equation (5) as below:

$\begin{matrix}{{G_{c} = {\frac{d}{x} = \frac{G_{a}\sqrt{\left( {\frac{R_{a}}{G_{a}} - \frac{R_{b}}{G_{b}}} \right)^{2} + \left( {\frac{B_{a}}{G_{a}} - \frac{B_{b}}{G_{b}}} \right)^{2}}}{x}}}.} & {{Equation}\mspace{14mu} (5)}\end{matrix}$

In some embodiments, if the ambient light does not include or includesinsignificant or negligible infrared light, the first Euclidean distancebetween the first image and the second image may be equal to x (i.e.,the second Euclidean distance between the second image and the thirdimage), and the G_(c) may equal to Ga. Accordingly, therefore the Gvalue of the visible light is G_(a).

In 714, the acquisition unit 510 may obtain an exposure value of theimaging device. The exposure value of the imaging device may include again, a shutter speed, an aperture size, sensitivity to light, or thelike, or any combination thereof. In some embodiments, the exposurevalue of the imaging device may include the gain, the shutter speed, andthe aperture size. In some embodiments, the exposure value of theimaging device may include the gain and the shutter speed.

In 716, the determination unit 520 may determine the brightness value ofthe visible light of the ambient light based on the first difference,the second difference, the G value, and the exposure value. In someembodiments, the determination of the brightness value of the visiblelight of the ambient light when the imaging device operates in differentoperation modes may be same with or different from each other.

When the imaging device operates in the night-operation mode, thebrightness value of the visible light of the ambient light may bedetermined according to Equation (6) as below:

Lum(night)=mean(X*Gc)/(xPos*sht*gain)  Equation (6),

where Lum(night) refers to the brightness value of the visible of theambient light in the night-operation mode, X refers to the seconddifference between the second image and the third image, Gc refers tothe G value related to the third image, mean(X*Gc) refers to the averageproduct of X and Gc of a subset of blocks of the third image, xPosrefers to the first difference between the first image and the secondimage (will be described in FIG. 8), sht refers to the shutter speed,gain refers to the gain of the imaging device.

In some embodiments, in step 702, the acquisition unit 510 may obtain aplurality of first images captured by the imaging device with visiblelight. In step 708, for each of the first images, the determination unit520 may determine a first difference between the each of the firstimages and the second image. The xPos in Equation (6) may be the maximumvalue of the first differences between the first images and the secondimage.

In some embodiments, if the imaging device operates in an automaticaperture mode, the aperture size of the imaging device may be adjustedautomatically according to different imaging scenarios. If the imagingdevice operates in the automatic aperture mode, the brightness value ofthe visible light of the ambient light in the night-operation mode maybe determined according to Equation (7) as below:

Lum(night)=mean(X*Gc)/(xPos*sht*gain*iris)  Equation (7),

where iris refers to the aperture size.

In some embodiments, the aperture of the imaging device may operate in amanual mode or an automatic mode. When the aperture operates imaging inthe manual mode, the iris may have a constant value. The value of theiris may be any positive number, such as 1.

If the imaging device operates in the day-operation mode, the imagingdevice may not receive the infrared light of the ambient light due tothe optical filter 150 having cut off the infrared light. The firstimage (i.e., the image captured by the imaging device with the visiblelight) and the third image (i.e., the image captured by the imagingdevice with the ambient light) may be the same. The second image (i.e.,the image captured by the imaging device with the infrared light) maynot be used to determine the brightness value of the visible of theambient light. The brightness value of the visible light of the ambientlight may be determined according to the first image or the third imageif the optical filter 150 operates in the day-operation mode. Forillustration purposes, the determination of the brightness value of thevisible light of the ambient light based on the first image is describedbelow as an example, and the determination may be based on the thirdimage. The determination unit 520 may divide the first image into aplurality of blocks. The determination unit 520 may determine a subsetof blocks from the plurality of blocks of the first image based on thebrightness value of each block. For example, the subset of blocks may bethe blocks whose brightness values are equal to or greater than athreshold. The determination unit 520 may also determine an averagebrightness value of the subset of blocks. In some embodiments, thebrightness value of a block may be determined by the determinationmodule 520 according to the RGB data of the block. For example, thedetermination module 520 may assign the R value, the G value, or the Bvalue of the block as the brightness value of the block. As anotherexample, the determination module 520 may convert the RGB data of theblock to Luminance-Bandwidth-Chrominance (YUV) data, and determine thebrightness value of the block based on the YUV data. For instance, thedetermination module 520 may assign the luma (i.e., Y) value as thebrightness value of the block.

The brightness value of the visible light of the ambient light in theday-operation mode may be determined according to Equation (8) as below:

Lum(day)=ev/(sht*gain)  Equation (8),

where Lum(day) refers to the brightness value of the visible of theambient light in the day-operation mode, ev refers to the averagebrightness value of the subset of blocks of the first image.

In some embodiments, if the imaging device operates in the automaticaperture mode, the brightness value of the visible light of the ambientlight in the day-operation mode may be determined according to Equation(9) as below:

Lum(day)=ev/(sht*gain*iris)  Equation (9),

where iris refers to the aperture size.

It should be noted that the above descriptions of process 700 areprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, various modifications and changes in the forms and details ofthe application of the above method and system may occur withoutdeparting from the principles of the present disclosure.

In some embodiments, one or more operations may be added or omitted. Forexample, 704 may be omitted in the day-operation mode of the opticalfilter 150. In some embodiments, the order of two or more operations maybe changed. For example, 702, 704, and 706 may be performedsimultaneously. As another example, 706 may be performed before 702 and704. In some embodiments, the first difference and the second differencemay be determined based on another color model, such as aHue-Saturation-Value (HSV) model, an HTML color model, a Hex tripletmodel, or the like, or any combination thereof. In some embodiments, thefirst difference and the second difference may be determined based onother parameters, such as an RGB vector angel, an HSV EuclideanDistance, an HSV Manhattan Distance or the like, or any combinationthereof. However, those variations and modifications also fall withinthe scope of the present disclosure.

FIG. 8 is a flowchart of an exemplary process for determining adifference between two images according to some embodiments of thepresent disclosure.

In some embodiments, at least part of process 800 may be performed bythe server 110 (implemented in, for example, the processor 201 of thecomputing device 200 shown in FIG. 2). In some embodiments, step 708and/or step 710 of the process 700 may be performed according to one ormore operations in the process 800. In some embodiments, the two imagesmay be any two of an image captured by an imaging device with visiblelight, an image captured by the imaging device with infrared light, andan image captured by the imaging device with ambient light describedelsewhere in this disclosure (e.g., FIG. 7 and the relevantdescriptions).

In 801, the acquisition unit 510 may obtain a fourth image. The fourthimage may be an image captured by an imaging device (e.g., the imageacquisition device 130). For example, the fourth image may be an imagecaptured by the imaging device with visible light, infrared light, orambient light. The ambient light may include visible light and infraredlight. More descriptions regarding the image captured by the imagingdevice with visible light, infrared light, or ambient light may be foundelsewhere of the present disclosure (e.g., FIG. 7 and the relevantdescriptions). In some embodiments, the acquisition unit 510 may accessa component in the image acquisition system 100, such as the storagedevice 140 or the storage module 430, and obtain the fourth imagepreviously captured by the imaging device and stored therein.

In 802, the acquisition unit 510 may obtain a first plurality of blocksof the first image. For example, the acquisition unit 510 may divide thefourth image into the first plurality of blocks. The sizes of the firstplurality of blocks may be same with or different from each other. Thefirst image may be divided into M*N blocks. The M and N may be anypositive number, respectively. In some embodiments, the first pluralityof block may be divided from a sub-region of the fourth image.

In 803, the acquisition unit 510 may obtain image data related to eachblock of the first plurality of blocks of the fourth image. The imagedata may include RGB data related to each block of the plurality ofblocks of the fourth image.

In some embodiments, a block may include one or more pixels. Thedetermination unit 520 may determine the RGB data of the block based onRGB data of the one or more pixels in the block. For example, the RGBdata of the block may be equal to an average value of the RGB data ofthe one or more pixels in the block.

In 804, the acquisition unit 510 may obtain a first subset of blocksfrom the first plurality of blocks based on the RGB data related to eachblock of the first plurality of blocks. In some embodiments, the firstsubset of blocks may be selected from the first plurality of blocksbased on the RGB data of the first plurality of blocks and an RGBthreshold. The RGB threshold may include an R value threshold, a G valuethreshold, or a B value threshold. The R value threshold, G valuethreshold, or B value threshold may be any number that is between 0 and255. The RGB threshold may be a default parameter stored in a storagedevice or a parameter set by a user of the image acquisition system 100via the image acquisition device 130. Alternatively, the RGB thresholdmay be determined by one or more components (e.g., the server 110) ofthe image acquisition system 100 based on the RGB data of the firstplurality of blocks. Merely by way of example, the RGB threshold may bean average R value of the first plurality of blocks.

In some embodiments, the first subset of blocks may be the blocks whoseRGB data are equal to or smaller than the RGB threshold. Forillustration purposes, assuming that the RGB threshold is an R valuethreshold, the first subset of blocks may be the block(s) whose Rvalue(s) is equal to or smaller than the R value threshold. In someembodiments, the first subset of blocks may be selected from the firstplurality of blocks based on the RGB data of the first plurality ofblocks and a plurality of RGB thresholds. In some embodiments, the firstsubset of blocks may be selected from the first plurality of blocksrandomly.

In 805, the determination unit 520 may determine a first average R/Gvalue and/or a first average B/G value of the first subset of blocksbased on the RGB data of each block of the first subset of blocks. TheR/G value may be a ratio of the R value to the G value. The B/G valuemay be a ratio of the B value to the G value. The first average R/Gvalue may be determined based on the R/G value of each block of thefirst subset of blocks. The first average B/G value may be determinedbased on the B/G value of each block of the first subset of blocks.

In 806, the acquisition unit 510 may obtain a fifth image. The fifthimage may be an image captured by the imaging device with visible light,infrared light, or ambient light. The fifth image and the first imagemay be captured by the imaging device with different types of light. Insome embodiments, the acquisition unit 510 may access a component of theimage acquisition system 100, such as the storage device 140 or thestorage module 430, and obtain the fifth image previously captured bythe imaging device and stored therein. Step 806 may be performed in asimilar manner with 801, and the detailed description is not repeatedhere.

In 807, the acquisition unit 510 may obtain a second plurality of blocksof the second image. For example, the acquisition unit 510 may dividethe fifth image into the plurality of second blocks. In someembodiments, the acquisition unit 510 may obtain the second plurality ofblocks from a sub-region of the fifth image. Step 807 may be performedin a similar manner with 802, and the detailed description is notrepeated here.

In 808, the acquisition unit 510 may obtain image data related to eachblock of the second plurality of blocks of the second image. The imagedata may include RGB data related to each block of the second pluralityof blocks of the fifth image. Step 808 may be performed in a similarmanner with 803, and the detailed description is not repeated here.

In 809, the acquisition unit 510 may obtain a second subset of blocksfrom the second plurality of blocks based on the RGB data related toeach block of the second plurality of blocks. In some embodiments, thesecond subset of blocks may include one or more blocks whose RGB data(e.g., an R value) is equal to or smaller than an RGB threshold (e.g.,an R value threshold). In some embodiments, the second subset of blocksmay be selected from the second plurality of blocks randomly. Step 809may be performed in a similar manner with 804, and the detaileddescription is not repeated here.

In 810, the determination unit 520 may determine a second average R/Gvalue and/or a second average B/G value of the second subset of blocksbased on the RGB data of each block of the second subset of blocks. Step810 may be performed in a substantially similar manner with 805 and isthe detailed description not repeated here.

In 811, the determination unit 520 may determine a difference betweenthe fourth image and the fifth image based on the first average R/Gvalue, the first average B/G value, the second average R/G, and thesecond average B/G value. In some embodiments, the difference betweenthe fourth image and the fifth image may be a Euclidean or a Manhattandistance between the fourth image and the fifth image. The Manhattandistance may be determined according to Equation (10) as below:

D1=|avg_R/G(1)−avg_R/G(2)|+|avg_B/G(1)−avg_B/G(2)|  Equation (10),

where D1 refers to the Manhattan distance, avg_R/G(1) refers to thefirst average R/G value of the fourth image, avg_R/G(2) refers to thesecond average R/G value of the fifth image, avg_B/G(1) refers to thefirst average B/G value of the fourth image, and avg_B/G(2) is the fifthaverage B/G value of the fifth image.

The Euclidean distance may be determined according to Equation (11) asbelow:

D2=√{square root over((avg_R/G(1)−avg_R/G(2))²+(avg_B/G(1)−avg_B/G(2))²)}  Equation (11),

where D2 refers to the Euclidean distance.

It should be noted that the above descriptions of process 800 areprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, various modifications and changes in the forms and details ofthe application of the above method and system may occur withoutdeparting from the principles of the present disclosure.

In some embodiments, one or more operations may be added or omitted. Insome embodiments, the order of two or more operations may be changed.For example, 801 and 806 may be performed simultaneously. As anotherexample, 806 may be performed before 801. In some embodiments, thedifference between the first image and the fifth image may be determinedbased on another color model, such as a Hue-Saturation-Value (HSV)model, an HTML color model, a Hex triplet model, or the like, or anycombination thereof. In some embodiments, the difference between thefourth image and the fifth image may be determined based on otherparameters, such as an RGB vector angel, an HSV Euclidean Distance, anHSV Manhattan Distance or the like, or any combination thereof. However,those variations and modifications also fall within the scope of thepresent disclosure.

FIG. 9 is a flowchart of an exemplary process for determining abrightness threshold related to an operation mode according to someembodiments of the present disclosure. In some embodiments, at leastpart of process 900 may be performed by the server 110 (implemented in,for example, the processor 201 of the computing device 200 shown in FIG.2). In some embodiments, step 606 of the process 600 may be performedbased on the process 900 for determining a brightness threshold relatedto the first operation mode.

In 902, the acquisition unit 510 may obtain one or more brightnessvalues of visible light of ambient light in a period. The period may beany continuous period when the optical filter 150 operates in theoperation mode. The duration of the period may be 30 seconds, 1 minute,3 minutes, or any other number. In some embodiments, the one or morebrightness values of the visible light of the ambient light may bedetermined according to the process 700 described in connection withFIG. 7.

In 904, the determination unit 520 may determine an average brightnessvalue based on the one or more brightness values of the visible light ofthe ambient light in the period.

In 906, the determination unit 520 may determine the brightnessthreshold based on the average brightness value. For example, thebrightness threshold may be determined by multiplying the averagebrightness value of the visible light of the ambient light by a presetcoefficient. The preset coefficient may be any positive number greaterthan 1, such as 1.1, 1.2. In some embodiments, the preset coefficientmay be a default parameter stored in a storage device (e.g., the storagedevice 140) or a parameter set by a user of the imaging device.

It should be noted that the above descriptions of process 900 areprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, various modifications and changes in the forms and details ofthe application of the above method and system may occur withoutdeparting from the principles of the present disclosure. However, thosevariations and modifications also fall within the scope of the presentdisclosure. For example, in 904, the determination unit 520 maydetermine another brightness value (e.g., a median value) of the one ormore brightness values of the visible light of the ambient light in theperiod. In 906, the determination unit 520 may determine the brightnessthreshold based on the brightness value.

FIG. 10 is a schematic diagram of an exemplary spectrum of infraredlight according to some embodiments of the present disclosure. In thespectrum, the x-axis refers to a wavelength of the infrared light, andthe y-axis refers to an infrared light absorbance. As shown in FIG. 10,the wavelength of the infrared light is in the range of 775 nm to 900nm. The wavelength of the infrared light corresponding to the peak ofthe spectrum is greater than 850 nm and less than 875 nm.

FIG. 11 is an image captured by an imaging device according to someembodiments of the present disclosure. The image illustrated in FIG. 11corresponds to a scene A.

FIG. 12 is schematic diagram illustrating a distribution of RGB datacorresponding to the image illustrated in FIG. 11 according to someembodiments of the present disclosure. The points corresponding toblocks in the image of the scene A illustrated in FIG. 11. Each block inthe image of the scene A may include a plurality of pixels. The RGBvalue of a block may be an average value of the RGB values of theplurality pixels in the block. The x-axis refers to an R/G value of theblock. The y-axis refers to a B/G value of the block. The z-axis refersto a G value of the block. The image of the scene A illustrated in FIG.11 may be regarded as the third image related to ambient light describedin connection with FIGS. 1 and 6.

FIG. 13 is a schematic diagram illustrating a relationship between Gvalue of the image illustrated in FIG. 11 and a difference between theimage illustrated in FIG. 11 and an image related to infrared lightaccording to some embodiments of the present disclosure. The imagerelated to infrared light is captured by the same imaging device withthe image of scene A. The image related to infrared light is captured inan experimental environment only including infrared light or reasonablyclose to only including infrared light described elsewhere in thisdisclosure (e.g., FIG. 7 and the relevant descriptions). The differencebetween the image of the scene A and the image related to infrared lightis a Euclidean distance between the two scenes.

As shown in FIG. 13, the x-axis refers to the difference between theimage of the scene A and the image related to infrared light. The y-axisrefers to the G value of the image of the scene A. The G value of theimage of the scene A is roughly negative correlated to the differencebetween the scene A and the scene related to infrared light.

It should be noted that the above descriptions of FIGS. 10-13 areprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, various modifications and changes in the forms and details ofthe application of the above method and system may occur withoutdeparting from the principles of the present disclosure. For example,the RGB data of the scene A may be distributed in any pattern. However,those variations and modifications also fall within the scope of thepresent disclosure.

Having thus described the basic concepts, it may be rather apparent tothose skilled in the art after reading this detailed disclosure that theforegoing detailed disclosure is intended to be presented by way ofexample only and is not limiting. Various alterations, improvements, andmodifications may occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested by this disclosure and arewithin the spirit and scope of the exemplary embodiments of thisdisclosure.

Moreover, certain terminology has been used to describe embodiments ofthe present disclosure. For example, the terms “one embodiment,” “anembodiment,” and/or “some embodiments” mean that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present disclosure.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the present disclosure.

Further, it will be appreciated by one skilled in the art, aspects ofthe present disclosure may be illustrated and described herein in any ofa number of patentable classes or context including any new and usefulprocess, machine, manufacture, or composition of matter, or any new anduseful improvement thereof. Accordingly, aspects of the presentdisclosure may be implemented entirely hardware, entirely software(including firmware, resident software, micro-code, etc.) or combiningsoftware and hardware implementation that may all generally be referredto herein as a “unit,” “module,” or “system.” Furthermore, aspects ofthe present disclosure may take the form of a computer program productembodied in one or more computer readable media having computer readableprogram code embodied thereon.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including electro-magnetic, optical, or thelike, or any suitable combination thereof. A computer readable signalmedium may be any computer readable medium that is not a computerreadable storage medium and that may communicate, propagate, ortransport a program for use by or in connection with an instructionexecution system, apparatus, or device. Program code embodied on acomputer readable signal medium may be transmitted using any appropriatemedium, including wireless, wireline, optical fiber cable, RF, or thelike, or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object-oriented programming languagesuch as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB. NET,Python or the like, conventional procedural programming languages, suchas the “C” programming language, Visual Basic, Fortran 2103, Perl, COBOL2102, PHP, ABAP, dynamic programming languages such as Python, Ruby, andGroovy, or other programming languages. The program code may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider) or in a cloud computing environment or offered as aservice such as a Software as a Service (SaaS).

Furthermore, the recited order of processing elements or sequences, orthe use of numbers, letters, or other designations, therefore, is notintended to limit the claimed processes and methods to any order exceptas may be specified in the claims. Although the above disclosurediscusses through various examples what is currently considered to be avariety of useful embodiments of the disclosure, it is to be understoodthat such detail is solely for that purpose and that the appended claimsare not limited to the disclosed embodiments, but, on the contrary, areintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the disclosed embodiments. For example,although the implementation of various components described above may beembodied in a hardware device, it may also be implemented as a softwareonly solution, for example, an installation on an existing server ormobile device.

Similarly, it should be appreciated that in the foregoing description ofembodiments of the present disclosure, various features are sometimesgrouped together in a single embodiment, figure, or description thereoffor the purpose of streamlining the disclosure aiding in theunderstanding of one or more of the various inventive embodiments. Thismethod of disclosure, however, is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, inventive embodiments liein less than all features of a single foregoing disclosed embodiment.

In some embodiments, the numbers expressing quantities or propertiesused to describe and claim certain embodiments of the application are tobe understood as being modified in some instances by the term “about,”“approximate,” or “substantially.” For example, “about,” “approximate,”or “substantially” may indicate ±20% variation of the value itdescribes, unless otherwise stated. Accordingly, in some embodiments,the numerical parameters set forth in the written description andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by a particular embodiment. Insome embodiments, the numerical parameters should be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of some embodiments of theapplication are approximations, the numerical values set forth in thespecific examples are reported as precisely as practicable.

Each of the patents, patent applications, publications of patentapplications, and other material, such as articles, books,specifications, publications, documents, things, and/or the like,referenced herein is hereby incorporated herein by this reference in itsentirety for all purposes, excepting any prosecution file historyassociated with same, any of same that is inconsistent with or inconflict with the present document, or any of same that may have alimiting affect as to the broadest scope of the claims now or laterassociated with the present document. By way of example, should there beany inconsistency or conflict between the description, definition,and/or the use of a term associated with any of the incorporatedmaterial and that associated with the present document, the description,definition, and/or the use of the term in the present document shallprevail.

In closing, it is to be understood that the embodiments of theapplication disclosed herein are illustrative of the principles of theembodiments of the application. Other modifications that may be employedmay be within the scope of the application. Thus, by way of example, butnot of limitation, alternative configurations of the embodiments of theapplication may be utilized in accordance with the teachings herein.Accordingly, embodiments of the present application are not limited tothat precisely as shown and described.

1-23. (canceled)
 24. A system for changing an operation mode of anoptical filter of an imaging device, comprising: a storage devicestoring a set of instructions; at least one processor in communicationwith the storage device, wherein when executing the set of instructions,the at least one processor is configured to cause the system to: obtaina first operation mode of an optical filter; determine a plurality ofbrightness values of visible light of ambient light in a period;determine, among the plurality of brightness values of the visible lightof the ambient light in the period, a count of brightness values of thevisible light of the ambient light that respectively satisfy a firstcondition; determine whether the count satisfies a second condition; andin response to determining that the count satisfies the secondcondition, switch the first operation mode to a second operation mode ofthe optical filter.
 25. The system of claim 24, wherein the firstoperation mode or the second operation mode includes a night-operationmode of the optical filter or a day-operation mode of the opticalfilter.
 26. The system of claim 24, wherein the first condition includesthat a brightness value exceeds or equal a first brightness thresholdand the second condition includes that the count exceeds or equal acount threshold.
 27. The system of claim 26, wherein to determine aplurality of brightness values of visible light of ambient light in aperiod, the at least one processor is further configured to cause thesystem to: for one of the plurality of brightness values of the visiblelight of the ambient light in the period, obtain a first image capturedby the imaging device with visible light, a second image captured by theimaging device with infrared light, and a third image captured by theimaging device with the ambient light; obtain an exposure value of theimaging device; and determine the brightness value of the visible lightof the ambient light based on the first image, the second image, thethird image, and the exposure value.
 28. The system of claim 27, whereinto determine the brightness value of the visible light of the ambientlight based on the first image, the second image, the third image, andthe exposure value, the at least one processor is further configured tocause the system to: determine a first difference between the firstimage and the second image; determine a second difference between thesecond image and the third image; determine a G value related to thethird image based on the second difference; and determine the brightnessvalue of the visible light of the ambient light based on the firstdifference, the second difference, the G value, and the exposure value.29. The system of claim 28, wherein the first difference or the seconddifference is determined based on one or more parameters including atleast one of a color model, a RGB vector angel, an HSV EuclideanDistance, or an HSV Manhattan Distance.
 30. The system of claim 29,wherein the color model includes at least one of a Hue-Saturation-Value(HSV) model, an HTML color model, or a Hex triplet model.
 31. The systemof claim 26, wherein the first brightness threshold includes an averagevalue of one or more brightness values of the visible light of theambient light, a median value of the one or more brightness values, or aratio of the average value of the one or more brightness values.
 32. Thesystem of claim 26, wherein the first brightness threshold is determinedby: obtaining a brightness threshold related to the second operationmode; obtaining at least one first image taken in the first operationmode and at least one second image taken in the second operation mode;and determining the first brightness threshold based on the brightnessthreshold related to the second operation mode, the at least one firstimage, and the at least one second image.
 33. The system of claim 24,wherein the count threshold is set by a user of the system.
 34. Thesystem of claim 24, wherein the first condition includes that abrightness value is below a second brightness threshold and the secondcondition includes that the count exceeds or equal a count threshold.35. The system of claim 34, wherein to determine a plurality ofbrightness values of visible light of ambient light in a period, the atleast one processor is further configured to cause the system to: forone of the plurality of brightness values, obtain a first image capturedby the imaging device with visible light and a second image captured bythe imaging device with the ambient light; and determine the brightnessvalue of the visible light of the ambient light based on the first imageand the second image.
 36. The system of claim 35, wherein to determinethe brightness value of the visible light of the ambient light based onthe first image and the second image, the at least one processor isfurther configured to cause the system to: obtain a first plurality ofblocks of the first image; obtain RGB data related to each block of thefirst plurality of blocks; obtain a first subset of blocks from thefirst plurality of blocks based on the RGB data related to each block ofthe first plurality of blocks; determine a first average RIG value and afirst average B/G value of the first subset of blocks of the firstimage; obtain a second plurality of blocks of the second image; obtainRGB data related to each block of the second plurality of blocks; obtaina second subset of blocks from the second plurality of blocks based onthe RGB data related to each block of second plurality of blocks;determine a second average R/G value and a second average B/G value ofthe second subset of blocks of the second image; and determine the firstdifference between the first image and the second image based on thefirst average R/G, the first average B/G, the second average R/G, andthe second average B/G value.
 37. A method comprising: obtaining a firstoperation mode of an optical filter; determining a plurality ofbrightness values of visible light of ambient light in a period;determining, among the plurality of brightness values of the visiblelight of the ambient light in the period, a count of brightness valuesof the visible light of the ambient light that respectively satisfy afirst condition; determining whether the count satisfies a secondcondition; and in response to determining that the count satisfies thesecond condition, switching the first operation mode to a secondoperation mode of the optical filter.
 38. The method of claim 37,wherein the first operation mode or the second operation mode includes anight-operation mode of the optical filter or a day-operation mode ofthe optical filter.
 39. The method of claim 37, wherein the firstcondition includes that a brightness value exceeds or equal a firstbrightness threshold, and the second condition includes that the countexceeds or equal a count threshold.
 40. The method of claim 37, whereinthe determining a plurality of brightness values of visible light ofambient light in a period includes: for one of the plurality ofbrightness values of the visible light of the ambient light in theperiod, obtaining a first image captured by the imaging device withvisible light, a second image captured by the imaging device withinfrared light, and a third image captured by the imaging device withthe ambient light; obtain an exposure value of the imaging device; anddetermine the brightness value of the visible light of the ambient lightbased on the first image, the second image, the third image, and theexposure value.
 41. The method of claim 37, wherein the first conditionincludes that a brightness value is below a second brightness thresholdand the second condition includes that the count exceeds or equal acount threshold.
 42. The method of claim 37, wherein the determining aplurality of brightness values of visible light of ambient light in aperiod includes: for one of the plurality of brightness values,obtaining a first image captured by the imaging device with visiblelight and a second image captured by the imaging device with the ambientlight; and determining the brightness value of the visible light of theambient light based on the first image and the second image.
 43. Anon-transitory computer-readable storage medium including instructionsthat, when executed by at least one processor of a system, causes thesystem to perform a method, the method comprising: obtaining a firstoperation mode of an optical filter; determining a plurality ofbrightness values of visible light of ambient light in a period;determining, among the plurality of brightness values of the visiblelight of the ambient light in the period, a count of brightness valuesof the visible light of the ambient light that respectively satisfy afirst condition; determining whether the count satisfies a secondcondition; and in response to determining that the count satisfies thesecond condition, switching the first operation mode to a secondoperation mode of the optical filter.